Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Erythropoietin (EPO) given subcutaneously (SC) once per week has been successful in the treatment of anemia in continuous ambulatory peritoneal dialysis (CAPD) patients. We have identified a population of CAPD patients that requires EPO administration once per week or less often. To determine if specific variables could be identified that would predict which CAPD patients would require infrequent EPO dosing, we reviewed the charts of all our CAPD patients who were receiving EPO as of 1 June 1992. Patients had to have been on CAPD for 3 months and EPO for 3 months to be considered for analysis. We identified 12 patients who required EPO once per week or less frequently (infrequent EPO) and 9 patients who required EPO more than once per week (frequent EPO). Parameters that were analyzed included age, gender, race, time on CAPD, history of gastrointestinal bleeding, exit-site infection or peritonitis in the last 60 days, diabetes, amount of dialysate instilled per day, and the number of exchanges per day. Laboratory data that were analyzed included hemoglobin, hematocrit, serum iron, total iron-binding capacity, ferritin, blood urea nitrogen (BUN), creatinine, BUN/creatinine ratio, albumin, total protein, parathyroid hormone, and aluminum. Categorical data were analyzed via chi-square, and numerical data were analyzed via the t-test. The infrequent EPO group required only 35% as much EPO as the frequent group to maintain hemoglobin and hematocrit, which were significantly greater. The only parameter that was different between the two groups was age (infrequent EPO 42 +/- 13.2 vs frequent EPO 55.8 +/- 11.9 years, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Adv Perit Dial 1993
PMID:Infrequent dosing of subcutaneous erythropoietin for the treatment of anemia in patients on CAPD. 810 57

We studied 38 patients (9 haemodialysis, 18 peritoneal dialysis, 11 advanced renal failure) over the first 12 weeks of erythropoietin therapy. In 14 iron-overloaded patients (ferritin > 500 micrograms/l the haemoglobin (+/- SEM) increased from 6.74 +/- 0.27 to 9.85 +/- 0.36 g/dl (P < 0.0001) entirely by mobilizing iron reserves (reduced from 1,220 +/- 73 to 739 +/- 111 mg, P < 0.0001). In the 24 non-overloaded patients (ferritin < 500 micrograms/l) the haemoglobin rose similarly from 7.04 +/- 0.18 to 10.70 +/- 0.36 g/dl (P < 0.0001), partly from iron reserves (depleted from 200 +/- 74 to -44 +/- 77 mg, P = 0.016) and partly from oral iron supplements (305 +/- 110 mg). In the overloaded patients the ferritin declined from 1057 micrograms/l (geometric mean, range 504-3699) to 317 micrograms/l (42-1505, P < 0.0001). In the non-overloaded patients it declined from 82 micrograms/l (8-461) to 45 micrograms/l (5-379, P = 0.016). The transferrin saturation (TS) in the overloaded patients appeared to decline from 38.3 +/- 7.2% to 24.0 +/- 3.7% but this was not statistically significant. In the non-overloaded the TS was unchanged (23.3 +/- 2.4 before and 28.1 +/- 3.6% after treatment). Considering all 38 patients together, the haemoglobin correlated negatively with the ferritin (r = 0.3731, P < 0.001) but not with the TS. The TS correlated with the serum ferritin initially (r = 0.75, P < 0.001) but not after the first 4 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)
Nephrol Dial Transplant 1993
PMID:Monitoring of iron requirements in renal patients on erythropoietin. 797 Jan 8

Haemodialysis patients with iron overload sometimes develop resistance to erythropoietin therapy due to 'functional iron deficiency'. It is known that this resistance may be overcome by iron supplementation; however, the latter could worsen haemosiderosis. Therefore, we treated four iron-overloaded haemodialysis patients who had developed relative resistance to erythropoietin (among whom three had features of 'functional iron deficiency') with ascorbic acid (500 mg intravenously after haemodialysis, 1-3 times a week). The erythropoietin doses were voluntarily kept unchanged during the study. After a latency of 2-4 weeks, haematocrit and haemoglobin had increased respectively from 26.5 +/- 0.7 to 32.7 +/- 0.4 vol% and from 8.8 +/- 0.3 to 10.8 +/- 0.2 g/dl (means +/- SEM, P < 0.001). While serum ferritin remained unchanged, transferrin saturation increased from 27 +/- 7 to 54 +/- 12% (P < 0.05), suggesting that ascorbic acid supplementation had allowed mobilization of iron from tissue burdens. In one patient, haematocrit declined after withdrawal of vitamin C and increased again after rechallenge. Also, ascorbate supplementation was continued after the study in two patients and allowed the erythropoietin doses to be decreased, 8 and 11 weeks, respectively, after the start of the trial. When a control group of seven patients with normal iron status and without resistance to erythropoietin were challenged in the same manner with ascorbate, no elevation of haematocrit or transferrin saturation was noted. We conclude that ascorbate supplementation may circumvent resistance to erythropoietin that sometimes occurs in iron-overloaded patients, in particular, in the setting of 'functional iron deficiency'.
Nephrol Dial Transplant 1995
PMID:Resistance to erythropoietin in iron-overloaded haemodialysis patients can be overcome by ascorbic acid administration. 852 94

Recombinant human erythropoietin (rHuEpo) seems to be more efficient when given subcutaneously (SC) instead of intravenously (IV) for therapy of anaemia in haemodialysis patients. This was a cross-over study designed to assess the efficiency of rHuEpo when given SC rather than IV in a 1 year follow-up. Sixteen patients received IV rHuEpo for 6 months, then SC rHuEpo for 6 months. They were four males and 12 females with a mean age of 56 years (range 15-82). Haemoglobin concentration ([Hb]) was kept at 10 g/dl and transferrin saturation (TS) at more than 25%. Mean [Hb] was 9.7 +/- 1.0 g/dl with IV rHuEpo and 9.9 +/- 0.9 g/dl with SC rHuEpo (NS). Transferrin saturation was 27% before rHuEpo, 31% with IV rHuEpo and 34% with SC rHuEpo (NS vs IV rHuEpo). Serum ferritin was 691 +/- 113 ng/ml before rHuEpo, 652 +/- 94 ng/ml with IV rHuEpo and 997 +/- 132 ng/ml with SC rHuEpo (P < 0.05 vs IV rHuEpo). Intact parathyroid hormone was 354 +/- 83 pg/ml before rHuEpo, 201 +/- 63 pg/ml with IV rHuEpo and 122 +/- 33 pg/ml with SC rHuEpo (NS vs IV rHuEpo). Doses of IV rHuEpo were 156 +/- 24 U/kg/week and SC rHuEpo 74 +/- 13 U/kg/week (i.e. a saving of 53%; P < 0.001). We conclude that subcutaneous administration of rHuEpo is twice as efficient as IV rHuEpo in patients with good functional iron reserve.
Nephrol Dial Transplant 1995
PMID:Subcutaneous versus intravenous administration of erythropoietin improves its efficiency for the treatment of anaemia in haemodialysis patients. 852 93

The efficient use of recombinant human erythropoietin (rHuEPO) requires adequate body stores of iron. In peritoneal dialysis (PD) patients, iron replacement is most commonly administered orally. In this study, we prospectively followed 7 stable PD patients following bolus intravenous infusion of 1 g iron dextran in an outpatient setting. At 12 weeks, significant (p < 0.05) increments in mean hematocrit from 29.13% to 34.85%, transferrin saturation from 10.15% to 29.33%, serum iron from 27.38 to 67.00 micrograms/dL, and serum ferritin from 150.30 to 331.40 ng/mL were observed. Post-treatment, there was less requirement of rHuEPO, and at six months there was a 26% reduction in the mean weekly subcutaneous rHuEPO dose. At 12 weeks, serum albumin increased significantly from 3.50 to 3.76 g/dL (p < 0.05). There was no abnormality in any of the measured liver function tests. No patient developed an adverse or allergic reaction. We concluded that bolus intravenous infusion of iron dextran is an effective and well-tolerated method of repleting iron stores, and will allow a more efficient and economic use of rHuEPO in PD patients.
Adv Perit Dial 1996
PMID:Efficacy of bolus intravenous iron dextran treatment in peritoneal dialysis patients receiving recombinant human erythropoietin. 886 93

Some chronic renal failure patients respond poorly to recombinant human erythropoietin (rHuEPO). In continuous ambulatory peritoneal dialysis (CAPD) patients, such a poor response may indicate inadequate dialysis or low body iron stores. To correct iron deficiency, once-a-week intravenous iron supplementation is recommended. However, hemodialysis patients receive iron supplements three times a week. This study was designed to compare the efficacy of iron supplementation between once-weekly and twice-weekly regimens. In both groups, rHuEPO doses were similar. Seventeen CAPD patients were studied. All had hemoglobin levels less than 10 g/dL. Ten patients were given 100 mg intravenous iron once weekly, and 7 were given 50 mg intravenous iron twice weekly until a total iron dose of 600 mg was achieved (stage I). The patients were crossed over to receive another 600 mg iron (stage II). Hematocrit increased significantly in patients receiving twice-a-week iron supplementation (+3.8% and 6%) compared to those receiving once-a-week iron supplementation (+1.3% and 1.4%) during stages I and II. The ferritin levels were not different between the groups. In conclusion, rHuEPO is more effective when administered with intravenous iron.
Adv Perit Dial 1997
PMID:The efficiency of fractionated parenteral iron treatment in CAPD patients. 936 Jun 61

A number of factors have been shown to limit the response to recombinant human erythropoietin (r-HuEPO). One major factor appears to be an inadequate iron supply to the bone marrow. Erythropoiesis is dependent upon a continuous supply of iron to the bone marrow. The rate at which iron can be drawn from existing stores may easily limit the rate of delivery for haemoglobin synthesis. This results in 'functional iron deficiency' which is distinct from 'absolute iron deficiency' caused by depletion of iron stores. At present there are three main parameters available to clinicians wishing to monitor iron status in their patients: serum ferritin and transferrin saturation (TFS), which are indirect measurements, and the percentage of hypochromic red cells, which directly reflects marrow iron status. Ferritin levels should be measured before starting r-HuEPO therapy to ensure adequate iron stores (>200 microg/l), and when patients move from the correction phase to the maintenance phase of therapy (have stores become depleted during the correction phase?). In addition, ferritin levels can give an indication of iron overload following excess parenteral iron administration. The TFS represents a balance between iron supply by stores and demand by bone marrow. A saturation below 20% probably indicates iron-deficient erythropoiesis. However, this is an indirect measure of marrow iron supply and wide fluctuations have been observed when determined at different time points. The percentage of hypochromic red blood cells is measured by flow cytometry and a hypochromic subpopulation of more than 10% (normal percentage <2.5%) indicates iron-deficient erythropoiesis. However, not all departments may have access to the required equipment. The aim of iron supplementation is to provide sufficient iron for the correction phase and to replace iron losses (1500-2000 mg/year in haemodialysis patients) during the maintenance phase of r-HuEPO therapy. This amounts to a daily iron need in the range of 5 7 mg, which is well above the normal dietary intake and absorptive capacity of the human intestine. Therefore, there is a need for intravenous iron, in particular when the patient has absolute or functional iron deficiency, is intolerant of oral iron, or is not complying well with the oral regimen.
Nephrol Dial Transplant 1998
PMID:Iron monitoring and supplementation: how do we achieve the best results? 956 84

One of the classic histologic forms of renal osteodystrophy is osteitis fibrosa, and its distinguishing characteristic is bone marrow (BM) fibrosis, caused by the activation of marrow parenchymal cells. A bone biopsy must be performed in order to establish the diagnosis of renal osteodystrophy. The clinical use of bone biopsy is restricted, however, due to the invasiveness of the procedure. In recent studies, bone scans have provided information useful for the differential diagnosis between osteomalacia and osteitis fibrosa. However, bone scans can not provide information on the bone marrow status. Bone marrow immunoscintigraphy (BMIS) using Tc-99m anti-granulocyte antibody (AGA), a highly sensitive test for the detection of bone marrow abnormalities which is also a noninvasive method, has rarely been reported in chronic renal failure (CRF). BMIS can provide information in patients with myelofibrosis. The purpose of this study was to evaluate the usefulness of BMIS in CRF patients with special regards to biochemical parameters. Nineteen CRF patients (13 men, 6 women; mean age: 48 +/- 11 years) in whom bone scintigraphy using Tc-99m MDP (methylene diphosphonate) showed the so-called superscan pattern were included in the study. Their primary renal diseases were chronic glomerulonephritis (n = 14), diabetes (n = 4), and polycystic kidney disease (n = 1). Modes of therapies were continuous ambulatory peritoneal dialysis (CAPD) (n = 13; mean duration: 9.5 months), HD (n = 5; mean duration: 7.8 months), and conservative treatment (n = 1). BMIS using Tc-99m labeled anti-granulocyte monoclonal mouse antibody BW250/183 was performed, and the results were compared with the biochemical parameters of the patients. According to the presence of BM expansion, which may represent marrow fibrosis, the 19 patients were divided into two groups: Group I (n = 7) with BM expansion and Group II (n = 12) with normal marrow distribution. The biochemical parameters and bone markers of Group I were compared with those of Group II. There was no significant difference in biochemical parameters (blood hemoglobin, serum ferritin, erythropoietin, BUN, creatinine) between the two groups. There were no significants difference in serum calcium, phosphorus, tartate-resistant acid phosphatase (TRAP), and intact parathyroid hormone (iPTH) between the two groups. Serum alkaline phosphatase (ALP) and osteocalcin were significantly (P < 0.05) higher in Group I than in Group II. These results suggest that patients with bone marrow expansion in BMIS have increased levels of ALP and osteocalcin, indicating an increased osteoblastic activity. BMIS may be useful for the detection of bone marrow expansion due to marrow fibrosis in renal osteodystrophy, and for the evaluation of the extent of bone marrow fibrosis.
Adv Perit Dial 1998
PMID:Bone marrow immunoscintigraphy (BMIS): a new and important tool for the assessment of marrow fibrosis in renal osteodystrophy? 1064 20

Effective management of early anaemia in the course of chronic renal insufficiency requires the following: (i) implementing an efficient diagnostic strategy to exclude common contributing factors; (ii) initiating epoetin therapy for the majority of patients; for and (iii) ensuring adequate iron supply erythropoiesis. Diagnostic inquiry is warranted whenever the haemoglobin concentration is below the normal range adjusted for age and gender. The most efficient diagnostic approach is to assume erythropoietin deficiency, exclude iron deficiency, and pursue further diagnostic tests only when red-cell indices are abnormal or when leukopenia or thrombocytopenia are also present. Macrocytosis should prompt an inquiry into alcoholism, B12 deficiency, or folate deficiency. Microcytosis suggests iron deficiency or thalassaemia. Associated cytopenias raise the possibility of alcohol toxicity, pernicious anaemia, malignancy, or myelodysplastic syndrome. Epoetin therapy is warranted whenever the haemoglobin concentration has fallen below 10.0 g/dl. To initiate therapy prior to dialysis, epoetin should be administered at an average dose of 100 IU/kg/week (80-120 IU/kg/week, 50-150 IU/kg/ week) by subcutaneous injection. Haemoglobin concentration should be monitored every 2 weeks and the epoetin dose adjusted by increments or decrements of 25% to maintain a rate of rise of haemoglobin concentration of 0.2-0.6 g/dl (0.3 0.6 g/dl/week, 0.2-0.5 g/dl/week). When the target range is achieved, the dose of epoetin should be continually adjusted to maintain a stable haemoglobin concentration. Transferrin saturation and ferritin concentration should be monitored monthly, and sufficient iron provided to maintain transferrin saturation above 20%. The lower the haemoglobin concentration, the greater the likelihood that future intravenous iron will be required. Oral iron supplements should be avoided, since they are costly, ineffective, and troublesome to patients. Finally, a blunted therapeutic response to epoetin therapy provides important diagnostic information and gnostic inquiry.
Nephrol Dial Transplant 2000
PMID:Management of early renal anaemia: diagnostic work-up, iron therapy, epoetin therapy. 1103 56

Owing to the lack of data dealing with the influence of polyglucose dialysis solution (PG-DS) on serum indicators of iron status, our study aimed at examining this problem in patients receiving PG-DS for the overnight exchange during treatment with continuous ambulatory peritoneal dialysis. We evaluated serum concentrations of iron, ferritin, and transferrin, total iron binding capacity (TIBC), and transferrin saturation (TSAT) at 1.6 +/- 0.8 months before introducing 7.5% PG-DS for an overnight 2 L exchange lasting about 10 hours (period I, n = 14), after 1.2 +/- 0.6 months of PG-DS administration (period II, n = 14), after 4.4 +/- 0.8 months of PG-DS administration (period III, n = 11), after 8.8 +/- 2.2 months of PG-DS administration (period IV, n = 9), and at 2.0 +/- 0.6 months after PG-DS discontinuation (period V, n = 11). Interference owing to PG-DS in laboratory determinations of serum iron parameters was excluded. Indices of nutritional status were also evaluated in all study periods. Significant differences in iron parameters were seen between periods I and III, or I and IV for transferrin (212 +/- 41 mg/dL vs 253 +/- 36 mg/dL), TIBC (304 +/- 40 micrograms/dL vs 338 +/- 31 micrograms/dL) and TSAT (34% +/- 15% vs 24% +/- 4%). After PG-DS withdrawal, these parameters all returned to pre-treatment values. Improvement in nutritional status was indicated by increases in total body mass (73.9 +/- 15.6 kg vs 77.4 +/- 13.8 kg), lean body mass (54.5 +/- 9.7 kg vs 56.9 +/- 8.5 kg), and serum total protein concentration (61.7 +/- 10.8 g/L vs 70.5 +/- 8.0 g/L). We conclude that serum transferrin concentration increases during PG-DS administration without enhanced iron binding to transferrin. An increase in transferrin level can be related to improved nutritional status.
Adv Perit Dial 2000
PMID:Polyglucose dialysis solution influences serum iron parameters. 1104 65


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